A communication system allocates a Transport Connection IDentifier (TCID) on a per service-flow basis to each mobile station (MS). Thus, a base station (BS) can identify if packets received through TCIDs received from MSs located in a service area are for any service flow of any MS. For example, when an MS requests uplink bandwidth allocation, the MS requests an uplink bandwidth on the basis of a CID allocated to a service flow. A BS confirms the service flow requesting the uplink bandwidth through the CID received from the MS.
One MS includes several CIDs and, thus, can simultaneously transmit packets for several CIDs. For example, if requesting an uplink bandwidth, an MS constructs and transmits uplink bandwidth request information on several CIDs as shown in FIG. 1. That is, the MS constructs an uplink bandwidth request message for several CIDs using a generic Media Access Control (MAC) header and a band request header.
FIG. 1 is a diagram illustrating a structure for transmitting packets for a plurality of CIDs in an MS of a communication system according to the conventional art. The following description is made assuming that packets of a plurality of CIDs including a CID included in a generic MAC header are transmitted.
As shown in FIG. 1, if requesting an uplink bandwidth, an MS 110 constructs a message including uplink bandwidth allocation request information on a CID #205 (hereinafter, referred to as “1st CID”) 101, a CID #302 (hereinafter, referred to as “2nd CID”) 103, and a CID #4331 (hereinafter, referred to as “3rd CID”) 105. At this time, the MS 110 includes the bandwidth allocation request information on the 1st CID 101 included in a generic MAC header 120 using a grant management sub header 130 of 2 bytes. The MS 110 includes the bandwidth allocation request information on the 2nd CID 103 and 3rd CID 105 using bandwidth request headers 140 and 150 of 6 bytes.
Thus, the MS 110 concatenates and transmits the generic MAC header 120, the grant management sub header 130, the bandwidth request header 140, and the bandwidth request header 150 to a BS. The generic MAC header 120 includes the 1st CID 101. The grant management sub header 130 includes a bandwidth information 102 required by the 1st CID 101. The bandwidth request header 140 includes a bandwidth information 104 required by the 2nd CID 103, and the 2nd CID 103 information. The bandwidth request header 150 includes a bandwidth information 106 required by the 3rd CID 105, and the 3rd CID 105 information.
The BS confirms the 1st CID 101 in the generic MAC header 120 of the message constructed as above, and confirms the bandwidth information 102 required by the 1st CID 101 in the grant management sub header 130. The BS confirms the 2nd CID 103 and the bandwidth information 104 required by the 2nd CID 103 through the bandwidth request header 140. The BS confirms the 3rd CID 105 and the bandwidth information 106 required by the 3rd CID 105 through the bandwidth request header 150.
After that, the BS allocates an uplink bandwidth to the MS according to a bandwidth required by each of CIDs.
As described above, if one MS transmits packets for a plurality of CIDs, the MS uses a grant management sub header of 2 bytes for a CID included in a generic MAC header. Also, the MS transmits a packet using a separate header for CIDs not included in the generic MAC header and thus, there is a problem of increasing an overhead.